Synthetic Oil - good or bad?

Hi all,
One thing not mentioned in this thread. Thermal conductivity. Like antifreeze to rich, won't
pick up heat or get rid of it. A couple posts mentioned problems with parts/ Ring & pinion
was one of them. 35yrs ago we hit 425degs in a hobby stock rear axle in only a 20 lap 1/2
mile heat with the top name synthetic gear oil. Melted the 400deg crayon and started on
the 450deg mark. Turned the ring gear teeth blue and the pinion dead soft. Gear oil came
out like water. We went down to the local farm co-op and picked up house brand 89/90 for
final. 25 laps touched the 300deg crayon never hit the 350deg. Pinion teeth half gone and
bearings bronze colored. Over 100deg difference synth to regular oil. About 30% cooler.
I managed fleet/industrial service and seen same trend. When you are reasponsable for
over $100million worth of equipment the buck stops with you. All my techs seen the
same thing as I had them test for it as a few remarked bullshtt. They tested and said
they would never have believed it.
My wife has a 2018 370Z roadster. 340hp v6. We had 5 free dealer $24/qt synth oil changes.
Car has oil temp gauge on top of dash, 310-340deg engine oil temp @ 75-85mph. Dealer
sez normal/best magic oil there is. OK. After second 3000mi change I used Napa house
same weight dino oil. NEVER broke 240deg oil temp going into 90deg+ summer after change.
This April auto store has Mobil 1 sale, Hmmm lets see. Back over 300+ deg oil temp.
Dumped that shttt out about 400mi later and put dino back in and could not break 240degs.
I can hit the front of the valve cover under engine cover with a temp gun and there is a
40-50deg difference between the 2 oils. Now I like my exaust springs to keep there tension
as the oil off the rocker is what cools them.
I have tested this with equipment/temp markers and this is what I have seen, not just
an untested opinion. 35yrs and same result, no change. Additive package yes, but this seems
to be a base stock issue. Additive package has min affect on thermal dynamics.
Something to think on, or test for your self. Has anyone else seen this temp trend?
I can duplicate it on my wifes 370Z and my TJ jeep 2.5l 4.88 rear axle
with just a oil change, any brand same thing. I ran across a trade paper about
this 6-8yrs ago and this thread has me thinking about this. Now when it
comes to cold start ect, outstanding. But

Thanks for reading about what I have seen,
Rick